After trying some less than desirable ohm meters, such as having a glob of wires and hot glue in the middle (some of you know the one), I got one that runs off a 14500 or USB cable and came with both! I don't think it came from Sigelei that way but it is a Sigelei and here is an article, Sigelei Ohm Reader, that gives all the specs and so forth on it. I know most use a AA alkaline battery and don't come with a power wire either. It only tests resistance but you can buy an adapter to check battery voltage also, I know it does not come with it but they are sold separately for a few bucks. So if you are looking for a decent little ohm reader this one will do the trick.